I love to talk about outboard engine maintenance and oil changing is one of my favorite topics. All four stroke outboard motors have a common denominator; every one has a crankcase that holds oil that is circulated throughout the engine for lubrication of all the internal moving parts.
The crankcase should always hold the right amount of the correct type of four stroke marine oil. There are differences! Engine oils do much more than just lubricate. There are three organizations that classify and rate marine engine lubricants. API - American Petroleum Institute, SAE - Society of Automotive Engineers, NMMA -National Marine Manufacturers Association.
For the best performance and protection, four stoke outboards should have the NMMA FC-W® rating. The advantages of FC-W® rated four stroke engine oils are:
● Far superior rust and corrosion protection, thanks to additives not available in today's passenger car oils.
● High levels of bearing protection, far more than in passenger car oils.
● High resistance to foaming under high engine speeds, foaming that can break down the oil's ability to provide the required lubricity.
● Superior lubrication even when fuel dilution potential is present. This is particularly important when boating in cold water under low-speed trolling conditions.
● Designed and tested by the marine industry for the marine industry.
(Courtesy of Yamaha Marine USA).
The first oil and filter change is at 20 hours of operation, with the next one being 80 hours later and then every 100 hours thereafter. Each manufacturer has their own specification for viscosity (i.e. 10w30, 10w40, etc.) and each has their own recommendations for quantities.
When changing oil always change the filter, service the lower unit fluid, use a new crush washer on the crankcase drain plug, pull the prop to check for fishing line behind the prop forward thrust washer, lube all grease fittings on the engine, and always ask for an engine history report. Reset the engine oil reminder on models so equipped.
Four stroke outboard engines are highly sophisticated, precision machines that will service your boating needs for a long time with just a little maintenance. Automotive oils are based on emissions standards and marine oils are formulated more for lubricity. Most four stroke outboards are designed to run 6000 rpm's, way more than your car, so for long engine life we stress using the correct oil.
Let's have a great season.